1. Field
The present teachings generally relate to the field of signal processing and more particularly, to a system and methods for improving the performance of detectors associated with signal imaging in biological analysis.
2. Description of the Related Art
During biological analysis, such as nucleotide sequencing or microarray processing, photo-detectors such as charge coupled devices (CCD) may be used to detect signals arising from labeled samples or probe features responsive to selected target analytes. These signals may take the form of fluorescent or visible light emissions that are desirably analyzed to quantify signal intensities arising from each labeled sample or probe feature and are subsequently resolved to quantitatively or qualitatively evaluate the presence of a target analyte within a sample.
Generally, a CCD used in such a biological analysis comprises an array of signal detecting pixels. The signal detection for a given pixel can be characterized as a conversion of an incident electromagnetic energy signal into a number of electron-hole pairs. The pixel may be configured to collect either the electrons or the holes thus generated with the number of collected charges representative of the incident energy. A CCD having a plurality of such pixels with collected charges can be read out by a sequence of shifting operations by applying a sequence of gate voltages to the pixels in a predetermined manner. The charge collected from a selected pixel can then be read out or quantitated and used for further analysis.
The operation of the CCD in the foregoing manner is facilitated by a plurality of operating parameters. In a conventional biological analysis system, these CCD operation parameters are generally set when a user receives the system. Although the set parameters may be generally suitable for the intended application of the CCD, they typically do not cover every possible analysis situations. Thus, the generally fixed configurations of certain CCD operating parameters may limit the manner in which the CCD is used in the biological analysis. Consequently, there is an ongoing need for an improved approach to the manner in which CCDs are used in biological analysis systems.